Nibbler



y 21, 1940- H. L. TRAUTMANN I I 2,201,599

NIBBLER Filed May 10, 1938 2 Sheets-Shee1 1 fimsmr L. 7/?Aur/v/1 /v/v,

INVENTOR.

I BY 1' NEY Patent d May 21, 1940 UNITED STATES? PATENT oFl-"lca .Herbert L. Trantmann, Loa Angelou, Calif aasignor to Douglas Aircraft Company, Inc., Santa Monica, Calif., a corporation of Delaware . My invention relates in general to nibblers, and relates in particular to a nibbler having certain I important features not present in the prior art.

the usual operation of the nibbler.

. It is common practice in the art to provide a.

, nibbler-which cuts metal sheets by a reciprocating cutting member having a movable cutting edge which moves past a fixed cutting edge and forms a slot in the sheet by shearing, such, for example, as is illustrated in the patent to Andersson, No. 2,035,448, issued March 31, 1936.

I have found it necessary, particularly in portable nibblers, to provide a nibbler with a stripper for holding the sheet being. cut from being raised or removed from proper position to be operated on by the upward or return stroke of the cutter member.

It is an object of this invention to provide a nibbler having a stripper of simple rugged construction and one which does not interfere wi It is an object of the invention togproviae a nibbler having a head with a projecting cutter member and means on its head for guiding or supporting the projecting cutter member and for ,guiding and holding the sheet which is being cut in working relation to the cutter means of the nibbler.-

In many instances it is necessary or advan-' tageo'us to start the out within the boundaries of the sheet to be out rather than at the edge thereof. Also it is frequently necessary or advantageous to perform a'cutting operation with the sheet or part in place where it is impossible" and arranged that it will pass through a starting opening formed in the work and may be with drawn transversely through the cut'which is formed by the cutting member of the nibbler. In

using a nibbler incorporating the features of my invention it is unnecessary to start the cut from or terminate the cut at the edges or boundaries of the sheet or part being cut, and furthermore it is not necessary to move the nibbler backwardly along the slot which is'cut to the edge oi the sheet or to the starting hole for removal of the nibbler. The portion of the nibbler which is extended through the work usually includes only the end of the cuttingmember and the stripper, and the stripper of my invention is preferably notquite as wide as the cutting member,

nibbler transversely.

and therefore not quite as wide as the slot which has been cut. This permits free removal of the It is a further object of my invention to provide a nibblerhaving a stripper wall positioned directly ahead of the cutting edges, this wall being formed on a stripper which is arranged substantially parallel to or symmetric to the path or line of cut made by the nibbler.

It is also an object of my invention to provide a nibbler including a stripper which is so constructed and arranged to give full vision to the cutting member, and particularly the cutting edge thereof, so that no difficulty will be had in following aiguide line or other guide indicia along which the cut is to be made.

'A further object. of the invention is to provide a nibbler which will readily follow an arc and may be used on sheet stock other than flat stock, and which nibbler has a mouth leading to the cutting members, which mouth is provided with means for varying the height thereof so that different thicknesses of stock may be cut.

A further object of the invention is to provide a nibbler assembled from simple parts capable of being readily machined to provide proper working alignment of these working parts, and wherein the upward extension of the cutting head of the device is minimized by the use of a novel cross-head, eccentric and linkage combination.

Furtherobjects and advantages of the invention will be brought out in the following part of the specification.

Referring to the drawings which are for illustrative purposes only:

Fig. 1 is a partly sectioned elevational view of a preferred embodiment of the invention.

Fig. 2 is a section taken on a plane represented by the line 2-2 of Fig.1. v

4 Fig. 3 is a fragmentary face view looking toward the cutting head, as indicated by the arrow 3 of Fig.2.

Fig. 4 is a fragmentary plan view looking down on the cutting head.

Fig. 5 is a fragmentary sectional view similar to the upper part of Fig. 1 showing the cutter member in lowered position. a v

Fig. 6 is a section taken on a plane (indicated by theline 6-6 of Fig. 1 and showing a portion of aplate in the process ofbeing cut by the nibbler.

As shown in Figs. 1 and 2 of the drawings, the

preferred embodiment of the invention'includes a body It having-therein a power means for driving a rotatable shaft I I with a crank, or eccentric motivating force from a flexible shaft connected with a motor, but preferably the power means consists of an electric motor disposed in the shell I3 which forms apart of the body l0 and which has a handle I4 projecting downwardly therefrom for manual engagement whereby the nibbler may be moved relative to the sheet or member which is to be cut, or whereby the nibbler may be supported on a bench, as by the gripping of the handle. in a vise.

The body l0 includes a cylindrical casing ii disposed with its axis transverse to the axis of rotation of the shaft I I and in such position that the lower cylindrical wall I thereof will lie below the eccentric i2 and the upper cylindrical wall II thereof will lie above the eccentric 12. A crosshead. I8 is disposed in the casing l0, this crosshead having upper and lower cylindrical portions is and 20 lying respectively above and below the eccentric l2 and being connected to-- gether by spaced vertical walls 2| defining an opening 22 in the cross-head in which the cocentric l2 revolves. An axial opening 2| extends downwardly from the opening 22 within the lower part of the cross-head l8 and across this Opening 23 pivot means in the form of a transverse pin 24 is placed. A connecting link 2| is provided which has an upper opening 20 to receive the eccentric l2 and a lower opening 21 to receive the pivot pin 24. This link 25 lies in the openings 22 and 23 and projects downwardly from the eccentric I2. By use of the construction shown, it is possible to use a relatively long cross-head and to properly support the same without undue upward projection of the casing I I by which the cross-head is supported.

The upper end of the cross-head ll has an externally threaded projection 2| to receive a cap 29, which, when it is screwed" down tightly in place, is locked in position by use of set screws 3|. A cutter member II is removably secured to the upper end of the cross-head by means of the cap 29 which has a coaxial recess 32 to receive a ring 33 having an upwardly converging inner face 34 to engage cooperating conical segments 35 which engage a channel 2| in the lower cylindrical end portion 31 of the cutter member When the cap 29 is screwed into place, the ring 33 holds the segment 45 against the outer end face of the threaded extension 24. The lower extremity 39 of the cutter member 2| projects into an axial opening 4| in the extension 2| of the cross-head It. The cutter member 3|,

above its lower end portion 31, comprisesa square bar 42 which extends through a square opening 4| in a cutter head 44 which is secured to the upper end of the cylindrical wall I! by means of a collar 45 having internal threads 46 to engageex'ternal threads 41 formed on the upper portion of the cylindrical wall ll, a locking ring 4| being provided to lock the collar 45 in place. The opening 43 is preferably formed by milling a slot 44.

inward from the back of the member 44 and subsequently filling a portion of the slot with a Plate a.

As shown in Fig. 4, the cutter head 44 has an upwardly projecting extension II, which is substantially rectangular incross-section. having a front face 5| and side faces 52, which, as shown in Fig." 2, join with inwardly converging faces '3 which meet the top .or outer end face 54 or: the head. This end face 54 is convexly arched from front to rear, and a portion of this end face '4 cooperates with a. portion of the wall I! of. the opening 4| to form a fixed cutting edge II. To cooperate with the cutting edge 44, the cutter member 3| is provided with a downwardly faced cutting edge formed in the projecting upper end 4| of the cutter member ii in such position that when the cutter member is raised, as shown in'Fig. l, the cutting edge II will be above the cutting edge and will be below the cutting edge 5| when the cutter member II is in lowered position, as shown in Fig. 5. The cutting edge 5! is given a slight slope, as shown in Fig. 2, and is formed by a wall II which defines the upper end of a recess formed in the front face 42 of the cutter member 8|.

A guide or stripper II for the projecting end 5| of the cutter member ii is provided in the form of a goose-neck, as clearly shown in Figs.

1 and 5, this goose-neck comprising a rear part 64 which projects outward from the head 44 adiacent the rear face ll of the cutter member ll and in guiding relation thereto, an outer part which extends forwardly from the upper end of the back part 44 and passes across the outer end ed through an opening II in the front part 41 of the goose-neck in suchposition that its inner end 12 will project into the mouth Either the lower end 12 of the screw or the end face 0 of the part |'I will serve as a stripper wall or stop for limiting the upwardmovement of-a plate or part to he out which is inserted into the mouth. The inner, face II of the front part 41, as shown in Fig. 5, lies in a positionto guide the front face portion 14 of the projecting end II, this face portion 14 being a continuation or a portion of the front face of the cutting member Ii.

' atthe. outer end of the plate l! which is received in the slot I4 extending from top to bottom of the head 44, such slot l4, as hereinbefore indicated, beingpreferably the same width as the opening 43 in which the cutter member 2| operates. Accordingly. the inner face 0 of the member I! may form the back face or wall of the opening 43. So that the nlbblerwill cut on an are orcurved line, such as the line 14 of Fig. 6, the end ll of the cutter member 2| is provided with sidefaces H which converge r'earwardly to meet the back face II of the cutter member SI. the result being that the back face I! is narrower than the front face 82. The back part |4 of the guide means 43 is likewise provided with side faces 1| which converge rearwardly, as shown in Fig.6. The

.lowerportionofthefrontpartllofthegooseneck 4| may be provided, if desired, with side faces 1| whichoonver'ge forwardly. Fig. 8 shows aportionof a-plate |l having an opening ll therein. The guide means or goose-neck may be passed through this opening ll and a slot l2 may be cut leading from the opening II. This opening |l need not be greater than one inch in a portion of the. outer end face of said head to diameter where the nibbler is provided with a cutter member of a quarter inch width, or substantially half the size of the cutter member disclosed in Fig. 6'. Due to the compactness and lightness of the nibbler, it may be readily applied to the sheet to be cut and may be easily guided to follow curved lines. Owing to 'the fact that the upper or outer end face 54 of the head 44 is relatively narrow-and is convexly arched from front to rear,'the nibbler may be employed to cut sheets or walls having a material curvature.

In order that the stripper and projecting end of the cutting member may be inserted into op-' erating position througha starting opening, such as 8| in Fig. 6, or through the slot which is cut, or .be removed from operating position transversely through the slot, the part 63 isarranged on a plane substantially parallel to or substan- .tially symmetric to the line or path of the cut versely through the slot 'which is cut. In 'addition to this, the particular shape of the gooseneckwhich' has the rear, front, and outer parts but no side parts does not cover or impairyisual access to the cutting edges on either side, withthe result that a guide line or guide indicia on the work may be very accurately followed.

On each downward stroke of the cutter member ii the I cutting edge 51. acts in shearing relation to the cutting edge 56 and will cut from a metal -plate, which is passed into proper position through the mouth 69, a small piece of such plate, such as the cutting .90 shown-in Fig. 5.

This cutting is formed in the recess SI and drops, downwardly therein, to be, carried to the .ex-

'terior of the head 44 through a space'or opening 9i whichleads downwardly and outwardly from the opening 43 in such position that it will connect the face or passage 92 formed by the recess with the exterior of, the head 44, whereby to discharge the cuttings at a point below the mouth proper followingof a line.

i! and below the sheet which is being cut, so that there can be no accumulation of cuttingson' theupper face of the sheet to interfere withfthe l I claim as my invention: v 1. In a nibbling device of the character described, the combination of: ahead having an opening leading inwardly from its outer end face, one side portion of said opening cooperating with form a fixed cutting edge; a movable cutter member disposed in said opening, said cutter member having an end which projects from said opening and has a cutting edge to cooperate with said fixed cutting edge; a stripper for preventing.

displacement of the material be1ng,cut-compris-.

ing a goose-neck extending from-theouter end of said head adjacent the rear face of said end, then brnding forwardly beyond the-extremity of said end and turning inwardly across the front face of said end'and stopping in spacedrelation to said end face of said head so as to leave a mouth leading to said fixed cutting edge,

said goose-neck being shaped to pass transversely through a slot formed by the nibbling device;

and means carried 'by said head in a positioninward of said outer end face thereof operative to reciprocate said cutter member insaid opening so as to produce a shearing movement of said cutting edge relative to said fixed cutting edge.

2. In a nibbling device of the character described, the combination of: ahead having an opening leading inwardly from .its outer end face, one side portion of said opening'corresponding with a portion of the outer end face of said head to form a 'fixed cutting edge; a'movable cutter member disposed in said opening, said cutter member having an end which projects from said opening and has a cutting edge to cooperate with said fixed cutting edge; a stripper for preventingdisplacement of the material being cut comprising a' goose-neck extending from the outer-end of said head adjacent the rear face of said end, then bending forwardly beyond the extremity of said end and turning inwardly across the front face of said end andstopping' in spaced relation to said end face of said head so as to leave a mouth leading to said fixed cutting edge, and stripper adjusting means supported by the front portion of said goose-neck and adjustable to vary the height of said mouth;

and means carried by saidhead in a position inward of said outer end face thereof operative to reciprocate said "cutter member in saidopening.

so as toproduce a shearing movement of said cutting edge relative to said fixed cutting edge.

3. In a 'nibblingdevice of the character described, the combination of: a head having an opening leading inwardly from its outer end face,

' one side portion of said opening cooperating with a portion of the outer end face of said headto form a fixed cutting edge;- a movable cutter member disposed in said opening, said cutter member having a recess in the front side there- -of facing toward said fixed cutting edge, there being a wall on said cutter member at the outer end of said recess forming a cutting edge cooperating with said fixed cutting edge, said recess ,being of such size with relation to saidsidewallportion of said opening as to iormv a passage for cuttings, and there being a space in said head leading from the exterior thereof to said opening in such position as to receive said cuttings from said passage, and .deliver same to the exterior:

:and means carried by said head in a position inward of said outer end face thereof operative in said opening soas to produce a shearing movement'of said cutting edgerelative to said fixedcutting edge.

4. In a nibbling device of the character described, the. combination of a head having an opening leading inwardly from its outer end face,

one side wall portion of said opening cooperative with a portion 8f the outer end face of said head ,to form a fixed cutting edge; a movable cutter member disposed in said opening, said cutter member having an end projecting from the fro'ht end of said opening provided on .its front facewith amovin'g cutting edge to cooperate with said fixed cutting edge, said cutter member having a front transverse face and side faces which converge rearwardly to the back face thereof so that'the rearward portion of said projecting end will be narrower. than the front'face thereof to enable said nibblingdevice to cut'on a radius; and a guide extending from said head adjaguiding relation thereto; said guide being lik cent said back me of said .projectingend and in wise tapered rearwardly and not extending beyond the side walls of said projecting end.

5. In a nibbling device of the character described, the combination of: a head having an opening leading inwardly from its outer end face,

one side wall portion of said opening cooperative with a portion of the outer end face of said head to form. a fixed cutting edge; and a movable cutter member disposed in said opening, said cut ter member having an end projecting from the front end of said opening provided on its front face with a moving cutting edge to cooperate with said fixed cutting edge, said cutter member having side faces which converge rearwardly to the back face thereof so that the rearward portion of said projecting end will be narrower than the front face thereof to enable said nibbling deviceto cut on a radius, and a goose-neck extending from said head, said goose-neck consisting only of a rearwardly tapering back part extending from said head adjacent said back face of said projecting end, an outer part extending across the outer end of said projecting end, and a front part extending inward from said outer part across the front face of said projecting end and defining a mouth leading to said cutting edges.

6. In anibbling device of the character described, the combination of: a body formed so as to be manually gripped and so as to be-moved relative to a sheet which is to be cut, said body having a head extending upwardly therefrom, said head having an opening leading inwardly from its outerend face; a reciprocating cutter member extending through said opening; power 7 means carried by said body, said power means having a rotating eccentric disposed below the inner end of said cutter member; a cross-head extending from the inner end of said cutter member and extending to a point below said eccentric; a pivot carried by said cross-head below said eccentric; and a downwardly extending link connecting the eccentric to said pivot.

7. In a nibbling device of the character described, the combination of: a head having an opening leading inwardly from its upper end face, one side portion of said. opening cooperating with a portion of the upper end face to form a fixed cutting edge; a movable cutter member disposed in said opening, said cutter member having a recess in the front side thereof facing toward said fixed cutting edge, there being a wall on said cutter member at the outer end of said recess forming an inwardly faced cutting edge cooperating with said fixed cuttingedge, said recess being-of such size with relation to said side wall portion of said opening as to form a e to receive cuttings, and there being a space in said head leading outwardly from said opening, in such position as to carry off cuttings from said passage; a portable body connected to said head at a point below the upper end thereof, said body being formed so as to be manually gripped and so that the nibbling device may be moved relative to a sheet which is to be cut; power means carried by said body and having a rotating eccentric below the inner end of said cutter member; a cross-head extending from said inner end of said cutter member and extending to a point below saideccentric; a pivot carried by said cross-head below said eccentric; and a downwardly extending link connecting said eccentric to said pivot.

8. In a' nibbler, thenmhbination including: a head having an outer end face, an opening connected to said end face, and a fixed cutting edge: a movable cutter in said opening having an end I portion which projects outwardly from said end cutting, said gooseneck being no wider than said' movable cutter and leaving the sides thereof exposed; and means for reciprocating said movable cutter to bring said movable cutting edge into shearing relation to said fixed cutting edge.

9. In a nibbler, the combination including: a head having an outer end face, an opening connected to said end face, and a fixed cutting edge; a movable cutter in said opening having an end portionwhich projects outwardly from .said end face and has a movable cutting edge; a stripper for said'endportion, said stripper consisting of a rear part extending'from said head along the back of said end portion, an outer part extending forwardly from said rear part beyond the end of edge into shearing relation to said fixed cutting edge. v

T L. TRAU'IMANN. 

